Method of and means for continuously spreading filaments



Jan. 22, 1957 DOLEMAN 2,778,065

METHOD OF AND MEANS FOR CONTINUOUSLY SPREADING FILAMENTS Filed Aug. 13, 1952 4 Sheecs-Sheet 1 INVEHTOR'.

TACK DOLEMA I) Jan. 22, 1957 J. DOLEMAN 'METHOD OF AND MEANS FOR CONTINUOUSLY SPREADING FILAMENTS 4 Sheets-Sheet 2 Filed Aug. 13, 1952 mvmm: AcK Down-mu B):

J. DOLEMAN Jan. 22, 1957 METHOD OF AND MEANS FOR CONTINUOUSLY SPREADING FILAMENTS 4 Sheets-Sheet 3 Filed Aug. 13, 1952 INVENTOR. A DO EMAN Jan. 22, 1957 2,778,065

METHOD OF AND MEANS FOR CONTINUOUSLY SPREADING FILAMENTS J. DOLEMAN 4 Sheets-Sheet 4 Filed Aug. 15, 1952 IHVENTORZ A K DO M 8Y1 United States Patent METHOD OF AND MEANS FOR CONTINUOUSLY SPREADING FILAMENTS Jack Doleman, Chadderton, England, assignor to The British Rayon Research Association, Manchester, England, a British association, and T. M. M. (Research) Limited, Rossendale, England, a British company Application August 13, 1952, Serial No. 304,149 Claims priority, application Great Britain August 14, 1951 16 Claims. (Cl. 19-65) This invention relates to a method of and means for opening and/or spreading continuous filaments and is particularly though not exclusively applicable to the spreading of continuous textile filaments from a relatively narrow thick clustre such as a tow or bundle into a flat sheet for further processing, as for example for forming same into a top as described in co-pending application for patent Serial No. 222,062, which has been abandoned.

The object of the invention is to provide a new and improved method of and means for eifecting the opening or spreading aforesaid.

vThe invention comprises the method of opening or spreading continuous textile filaments consisting in pulling the filaments endwise and in the form of an endless tow or bundle through a passage while simultaneously subjecting themto the action of a contra-flow air draught, whereby said filaments, whilst under tension of the air draught, are free to separate laterally and induced to "assume an opened or spread order.

The method aforesaid may include the feature wherein the air flow is so directed relative to the filaments as to cause the filaments to spread laterally over the or part of the surface of the passage; or wherein the air flow is so directed relative to the filaments as to cause the filaments to be airborne adjacent to, or against, the upper surface of the passage.

The invention also relates to apparatus for spreading textile filaments comprising a tubular passage, means for drawing or pulling said filaments in the form of an endless tow or bundle into and through said passage, and means for simultaneously subjecting said filaments to the action of a contra-flow air draught, whereby said filaments whilst under tension of the air draught are free to separate laterally and induced to assume an opened and/or spread order.

Preferably the passage comprises an air duct which converges towards a throat of elongated cross-section, the converging part equalizing any uneven pressure distribution originating in the fan and supply ducts, the throat being followed by a slightly diverging zone in which the on-coming filaments may be airborne and free to open or spread laterally before being drawn through the throat in spread relationship. The variation of shape and sizes of the cross-section of the duct along its length is such that it creates equal pressure distribution and appropriate air speed during the action of the air on the filaments.

In the accompanying drawings:

Fig. l is a perspective view of one example of apparatus constructed in accordance with the invention and designed primarily for spreading continuous filaments initially in the form of a cable or tow.

Fig. 2 is a part sectional elevation in the line 2-2 Fig. 1.

Fig. 3 is a diagram of a further example of apparatus opening or spreading continuous filaments in cable or tow form.

2,778,065 Patented J an. 22, 1957 Fig. 4 is a perspective view of a still further example i of apparatus constructed in accordance with the in lines 77, 8-8, 99 and 1010, Fig. 6 respectively. I

In the example illustrated in Figs. 1 and 2 the apparatus comprises a horizontal air duct 10 having an initial portion 10a, of uniform cross-section of say 10 x 6 inches. One end of the initial portion of the duct is connected to the delivery side of an air blower (not shown), whilst the other end merges into the operative portion of the duct, the roof 10b of which, after a slit 11 to allow exit of the spread filaments t first declines sharply to form a converging zone and then inclines more gradually to provide a diverging zone and a throat 12, which acts as a transverse direction-changing surface for the filaments. The throat is necessary to spread the tow or bundle t to ribbon form 2 The outer end 10c of the air duct is open and at its upper edge there is a transverse bafiie 13 intended to cause air turbulence. It will be noticed that the bottom of the operative portion of the duct is a fiat, plane surface, but a curved plate 13a is provided located within the duct and below the more gradually inclined upper surface of the diverging able means may be provided for driving the roller and apron, and such apron and roller may comprise the feeding means of atow-to-top conversion apparatus described and illustrated in co-pending application for patent Serial No. 222,062.

In operation, the tow of continuous filaments in the.

sliver can or other suitable package located below the open outer' end of the air duct, is threaded through the operative portion of the duct and out through the slit 11 to the nip between roller 14 and apron 15. For facili tating threading, the top of the operative portion of the duct may be removable.

When the air blower (not shown) is brought into operation and the feed roller rotated, the filaments, are drawn through the operative portion of the air duct against the" contra-fiow air-current. The air current holds the filaments air-borne pressing them adjacent to or against the top surface of the duct. At the outer end of the duct the filaments t, by their weight, hang downwardly across the air current and float with a lot of movement which balloons them from the tow form and initiates the'opening or spreading while evening-up the tension in the individual filaments. On the steeply inclined diverging part of the duct the air current presses the spread fibres firmly against the top surface, thus causing a definedbending or deflection at the transverse edge where change of direction occurs, and the combined action of tension": on the filaments and deflection 'at such transverse edge A completes the spreading of the filaments laterally and brings them together 'into a thin uniformly spread sheet t which is maintained in the slit 11 and betweenithe nip of roller 14-and a'pron 15. t a

In Fig. 3 of the drawings, the apparatuscomprises a passage in the form of an air duct ainto oneendof which anendless tow or bundle-of continuous filaments b is'fed from a sliver can c. The filaments are subjected to the action of a contra-flow air draught from a blower d whereby said filaments whilst free but under tension of the air draught are induced to assumean opened and spread order, prior to being drawn inopened or spread relationship through the outlet tube f by'the nip rollers In the example illustrated by Figs. 4 and 5, the air duct .16 is mounted on a wheeled carriage 17 adaptedto move to and'fro on rai1s'18 audto enable'the reciprocationpf the carriage to be effected by.chains l9. A..bellows device 2th, is located between the initial portion 16a of theduct and .the air blowerZOa to allow reciprocation of the carriage. The initial portion of the duct is of round cross-section .Which converges into a'throat. 21- of. substantially elongated rectangularcross-section and preferably the end portions of the throat may be semicircular insteadrof flat, as shown in the figure, so as to .prevent undesirable secondary (eddy) flow inithe corners. It will be noted in'this examplethat both the top and bottom of the. operativeportion of the duct are inclined towards each otherand this construction assists equalizing of air pressure across the throat.

The operative portion of the duct has closure side membersZZ, 23 attached to the carriage, and a portion of side member 23 has been broken away to disclose the throat andtheexit slit-like aperture 24. The spread filaments in the ribbonjform are drawn throughthe convergingportion of the duct andthen through the exiLaperture by rollers 25, 25 rotatably mounted on the carriage prior to being plated down onto a conveyor apron or lattice (notshown) by the reciprocating movement imparted to said carriage.

As distinct from the example illustrated'by. Figs. 2 and 3 both the top and bottom portionsof the outer end of the .duct are inclined outwardly to providean expansion zone. 16b and it has been found in practice that the best results are obtained if the taper does not exceed 1'5, as otherwise the air jet will separate from the walls.

It is obvious that the construction illustrated in Figs. 4 and'S need not necessarily be mounted on a traversible. carriageif plating down of the spread filaments is not required in any particular process.

It has also been found by experiment that the apparatus illustrated 'in Figs. 4 and 5. givessuccessful spreading of continuous filaments, e. g. of 1% denier, ifthefollowing conditions are observed:

Speed-of contra-air flow at .fan exit" 60. tit/sec.

No. offilaments in tow or-bundle. 200,000approx. Speed of tow 10 ft./min.'approx. Initial diameter of tow-.. 1" approx.

Width of ribbon of spread filaments 9" approx.

This embodiment of the invention consists therefore essentially of three portions: a converging zone, a throat and-a divergingpart. Their mutual geometrical arrangement allows several possibilities. Thus, forinstance, the length of the throat may be comparable with that of the converging section; or it may be quite :short being .essentially the cross-section where the diverging section is directly connected to the converging one; or, some or all, ofthe-aforesaid. three sections may or may :not be symmetrical with respect to the axis, or lastly, the wallsof theducts may be plane or curved.

As. indicated/in Figs. 6 to 10, the operative portion of the duct may comprise a, single casting ZGhavingan eXit aperture 27 in the converging .zone 2.6a, the latter-at its flanged airenlry end being of circular cross-section (Fig. IQ) and converging to rectangular cross-section wi h semicircular-ends (Fig. 7) at the throatg28. At the.. air exit ortow; entry -;end I of the, expansion zone: 25b, theduct again diverges so that it is of circular cross-se tion.-

ilmallihe xample ill str e by F g .2 .of the dr ings the exit p m tefor the spreadfilaments lhQ'PHWidQdA ith a.- .mall;r ller 29 tsee- Fia-HD.

facilitate withdrawal of the filaments and to prevent chafing thereof. It is also important that all corners within the duct should be rounded ed to avoid secondary flow and the internal surfaces should be smooth, whilst the cross sections should not change rapidly.

What Lclaimis:

1. "Method of opening and spreading continuous filamerits, comprising the steps of pulling at a point in a passage spaced froman open end of-the same a bundle of filaments entering said passage at said :open end and pulled to said open end from a supply point'located-outside of and transversely spaced from said passage; and directing a stream of gaseous matter at said bundle of filaments passing in countercurrent to the pulled bundle of filaments through saidpassage and thereby tensioning said bundle of filaments within said passage against the pull, said stream of gaseous matter leaving said passage at the open end thereof, and hitting said bundle of filaments transversely, thereby causing, said filaments to open and spread before entering said passage.

2. Method of opening and spreading continuous filaments, comprising the steps of pulling at a point in apassage spaced from an open end'ofythe same a'bundle of filaments entering said passage at said open end and pulled to-said open end froma supply point located outside of and transversely spaced from said passage; and directing a stream of gaseous matter against one side-of saidbundle of filaments, said stream of gaseous matter passing in countercurrent to the pulled bundle of filaments through said passage urging said bundle of filaments against an inner surface of said passage and 'into a position extending in the direction of'said stream of gaseous matter and thereby tensioning said bundle of filaments within said'passage against the pull, said stream of gaseous matter leaving saidpassage 'atthe open'end thereof, and hitting said bundle of filaments-transversely, thereby causing saidfilaments toopen and spread beforeentering said passage.

" 3. Apparatus for -spreading continuous filaments, comprising, in combination, a passagehaving two open ends and an opening between said open ends; 'filamentsupply means located longitudinally and transversely spaced from one open-end of said passage; pullin-gmeans outside of and transversely spaced fromsaid opening and said passage for pulling a bundle of filaments from said supply means through said passage and throughsai'd opening; and blower means at said other end ofsaidpassage for blowing a stream of gaseous-matter vin countereurrent to said bundle of pulled filaments through-said passage, whereby said bundle of'filaments'isttensioned in said vipassage against the. pull, while a portion of saidtbundle located adjacent saidsupply means is transversely hit by said stream of gaseous matter and'opened andspread.

4. Apparatus for spreading continuous filamentsycomprising, in'combination, a passagehaving'two opemen'ds andanopening between saidopen ends andan inner face, between said. opening-and one ofsaidopen ends; filament supply means located longitudinally and transversely spacedfrom said onev open'end of said passage; pulling:

means outside of :said passage and transversely spaced from said opening and said passage. for pullingua bundle of filaments. from said supply means; through :said ha sage and alongsaid inner face and throughsaid opening; and blower :means. at .said other end .of. said passage for blowing a strearnof gaseous matter in countercurrent to said bundle of pulled filaments through said passage, Whereby'said bundle of filaments isgpressed against the inner face and -.tensioned in-said passage-againstthe pull, while a portion of said hHDdlG' IOCMRd ,adjacentsaidsupplyrneansis ,transverselyhit by said streamof gaseous matter and opened and spread.

:5 Appar tus for spread ng om n mu fil ments, comprising, in combination, a passage having two open ends-- and: an-openingbetween said. open endsandzan inner face between said owning and ,one.- of said -;open ends,. s aid inner face having a projecting tensioning edge constricting said passage; filament supply means located longitudinally and transversely spaced from said one open end of said passage; pulling means outside of said passage and transversely spaced from said opening and said passage for pulling a bundle of filaments from said supply means through said passage against said tensioning edge and along said inner face and through said opening; and blower means at said other end of said passage for blowing a stream of gaseous matter in countercurrent to said bundle of pulled filaments through said passage, whereby said bundle of filaments is pressed against the inner face and against said tensioning edge and tensioned in said passage against the pull, while a portion of said bundle located adjacent said supply means is transversely hit by said stream of gaseous matter and opened and spread.

6. Apparatus for spreading continuous filaments, comprising, in combination, a passage having two open ends and an opening between said open ends and an inner face between said opening and one of said open ends, said inner face having a projecting tensioning edge constrict ing said passage said inner face being composed of two inner face portions extending at an angle to each other from said projecting tensioning edge in opposite directions to said opening and said one end of said passage, said inner face portions receding transversely toward said opening and said one end; filament supply means located longitudinally and transversely spaced from said one open end of said passage; pulling means outside of and transversely spaced from said opening and end of said passage for pulling a bundle of filaments from said supply means through said passage against said tensioning edge and along said inner face and through said opening; and blower means at said other end of said passage for blowing a stream of gaseous matter in countercurrent to said bundle of pulled filaments through said passage, whereby said bundle of filaments is pressed against the inner face portion associated with said other end and tensioned in said passage against the pull, while a portion of said bundle located adjacent said supply means is transversely hit by said stream of gaseous matter and opened and spread.

7. Apparatus for spreading continuous filaments, comprising, in combination, a passage having two open ends and an opening between said open ends and an inner face between said opening and one of said open ends, said inner face having a projecting tensioning edge constricting said passage said inner face being composed of two inner face portions extending at an angle to each other from said projecting tensioning edge in opposite directions to said opening and said one end of said passage, said inner face portions receding transversely toward said opening and said one end and forming flaring portions in said passage; a curved wall located in said passage adjacent said one end of the same, said wall having an inwardly projecting face constricting part of the flaring end portion of said passage associated with said one end; filament supply means located longitudinally and transversely spaced from said one open end of said passage; pulling means outside of and transversely spaced from said opening and end of said passage for pulling a bundle of filaments from said supply means through said passage against said tensioning edge and along said inner face and through said opening; and blower means at said other end of said passage for blowing a stream of gaseous matter in countercurrent to said bundle of pulled filaments through said passage, whereby said bundle of filaments is pressed against the inner face portion associated with said other end and tensioned in said passage against the pull, while a portion of said bundle located adjacent said supply means is transversely hit by said stream of gaseous matter and opened and spread.

8. A method of opening and spreading continuous textile filaments consisting in pulling the filaments endwise and in the form of an endless tow or bundle into a passage, and simultaneously subjecting said filaments to a' contra-flow air draught, said filaments being caused to 6 undergo a change of direction at a region where they are subject to the influence of said air draught so that they are tensioned by said draught against the endwise pull but, before and up to said change of direction are rela= tively untensioned and free to be opened and spread by said draught.

9. A method of opening and spreading continuous textile filaments consisting in pulling the filaments substantially endwise into a passage, simultaneously passing a contra-flow of air through said passage, said filaments being caused to lie over their length of travel through said passage initially in one direction and then in another direction at an angle to the said one direction and to said contra-flow of air, and supporting the filaments against the air flow only after their change of direction so that they are there tensioned against the endwise pull but, before said change of direction is completed, are free to be opened and spread by said air flow.

10. Apparatus for opening and spreading continuous textile filaments comprising in combination a tubular passage, means for pulling said filaments endwise in the form of an endless tow or bundle into said passage, means for directing within said passage a contra-flow air draught onto said filaments, and means for causing said filaments to undergo a change of direction at a given region where they are subject to the influence of said air draught so that they are tensioned by said draught against the endwise pull but, before and up to said change of direction are relatively untensioned and free to be opened and spread by said draught.

ll. Apparatus for opening and spreading continuous textile filaments comprising in combination a tubular passage, pulling means for pulling said filaments substantially endwise in the form of an endless tow or bundle into said passage, means for simultaneously passing a contra-flow of air through said passage, means for causing said filaments to lie over their length of travel through said passage initially in one direction and then in another direction at an angle to the said one direction and to said contra-flow of air, and means for supporting said filaments against the air flow after their change of direction in the region of said pulling means so that they are there tensioned against the endwise pull but, before said change of direction is completed, are free to be opened and spread by said air flow.

12. Apparatus for spreading continuous textile filaments comprising in combination, a tubular passage, means for pulling said filaments substantially endwise in the form of an endless tow or bundle into said passage, an air blower connected to said passage capable of passing a contra-flow of air axially through said passage, a direction changing surface in said passage forming a throat, and a narrow transverse exit for said filaments defined by the leading edge of said direction changing surface and a wall of the passage, said means for pulling being aligned so as to draw the filaments over the part of the direction changing surface between said throat and said exit before passing through said exit, so that the filaments, after passing said throat are tensioned by the air flow against the endwise pull but, before passing said throat are free to be spread laterally by said air flow.

13. Apparatus as set forth in claim 12 in which said passage consists of an air duct, one end of which is connected to the delivery side of the air blower, and which converges towards a throat of transversely elongated cross-section, before diverging to form a zone in which the oncoming filaments are free to open or spread before being drawn through the throat in spread relationship.

14. Apparatus asset forth in claim 13 in which the cross-section of the air duct changes from circular, where it is connected to the blower, to substantially rectangular, at the throat.

15. Apparatus as set forth in claim 14 in which the cross-section of the air duct at the throat has outwardly arcuate ends.

7 16. Apparatus as set fogth in rglajm 13 in :which the lower transverse :wall :of the passage is fiat? and, -in which, the diverging part an upwardly co 1 1vex bafiie ;plat e is provided, forming a VenturLshape with the oppositewall.

Refgrgnces Cited in the file of this patent UNITED STATES PATENTS Minton Aug. 10, 1926 Bailey Mar. 1, 1932 Childs Jan. 9, 1 940 Mummery July 3, 1945 Roden Nov. 13 1951 

